Binding of Na+, Mg+, and Al+ to the π Faces of Naphthalene and Indole: Ab Initio Mapping Study
Binding of Na+, Mg+, and Al+ to the π Faces of Naphthalene and Indole: Ab Initio Mapping Study
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DOI：
10.1021/jp981371t
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发表时间：
1998-10
影响因子：
2.9
通讯作者：
R. Dunbar
中科院分区：
文献类型：
--
作者：
R. Dunbar
计算了Na+、Mg+和Al+与吲哚的整个π面区域和萘面长轴附近部分的结合能图。结合位点存在的所有三个阳离子的苯环和吡咯环的吲哚，虽然Na+的吡咯网站几乎消失。吲哚的苯基结合位点在所有情况下比吡咯位点稳定约4 kcal mol-1，比萘中的类似位点稳定约6 kcal mol-1。哈特里-福克的计算表明，在吲哚的氮原子上，开壳层Mg+离子有一个额外的稳定结合位点，但这个位点没有被密度泛函计算重现，很可能是计算的假象。本文考虑了一种微分静电图象，其中吲哚的π面在其阳离子相互作用中与萘的π面等效，外加一个微分静电场，该静电场等于萘的π面与吲哚的π面之间的静电场差。
Binding energy maps have been calculated for the binding of Na+, Mg+, and Al+ to the entire π-facial region of indole and to the parts of the naphthalene face near the long central axis. Binding sites exist for all three cations over the phenyl ring and over the pyrrole ring of indole, although for Na+ the pyrrole site almost disappears. The phenyl binding site of indole is in all cases about 4 kcal mol-1 more stable than the pyrrole site and about 6 kcal mol-1 more stable than the similar site in naphthalene. The Hartree−Fock calculations suggested an additional stable binding site for the open-shell Mg+ ion over the nitrogen atom of indole, but this site was not reproduced by density-functional calculations and may well be a computational artifact. A differential electrostatic picture is considered in which the π face of indole is equivalent, in its cation interactions, to the π face of naphthalene, with the addition of a differential electrostatic field equal to the difference in the electrostatic fiel...